Why does only one reverse light on a Cadillac illuminate?

[LeMadelyn]

It is normal for only one reverse light on a Cadillac to illuminate because the other one is a fog light. Having a single reverse light makes it easier to catch the attention of drivers behind and prevents confusion with brake lights. In many developed countries, only one reverse light is permitted, which has been written into law. Introduction to reverse lights: When the car is put into reverse gear, the reverse light switch activates the reverse light circuit, causing the white reverse light at the rear of the vehicle to illuminate. This warns vehicles and pedestrians behind and also serves as illumination. Some vehicles are equipped with reverse beepers or voice warning devices that emit sound signals while reversing to indicate the car is moving backward. How reverse lights work: The reverse light switch operates as a normally open switch (normally disconnected). When the reverse gear is engaged, the mechanical mechanism presses down the switch contacts, closing the circuit and turning on the reverse light and activating the reverse warning sound. When the reverse gear is disengaged, the switch contacts spring back, and the reverse light circuit returns to an open state.